Request not passed in proxy_mangle_response along with response

```
Request should be passed along with the response in proxy_mangle_request. This 
is so that each response can be tied to the corresponding request. Currently 
there is no way of knowing which response each request belongs to.

```

Original issue reported on code.google.com by `sohail.r...@gmail.com` on 29 Jan 2015 at 5:12
